Buck/boost method of voltage regulation for a permanent magnet generator (PMG)

Abstract

The output voltage generated by permanent magnet generator (PMG) is regulated by controlling a buck/boost voltage applied to selected sub-coils within the PMG. The PMG includes a number of stator coils that are each divided into a number of sub-coils. A buck/boost voltage source generates a buck/boost voltage, and a controller connected to monitor the output voltage generated by the PMG selectively applies the buck/boost voltage to selected sub-coils based on the monitored output voltage. In this way, the controller is able to regulate the output voltage by selectively controlling the buck/boost voltage applied to the selected sub-coils.

1. A permanent magnet generator (PMG) system for regulating an output voltage, the system comprising:
 a permanent magnet generator (PMG), comprising:
 a rotor; 
 a stator having stator teeth; and 
 stator coils wrapped around the stator teeth and divided into sub-coils, wherein a first set of sub-coils is connected in series to generate the output voltage; 
 
 a buck/boost voltage source for producing a buck/boost voltage; and 
 a controller connected to monitor the output voltage and to apply the buck/boost voltage to selected sub-coils not connected to the first set of sub-coils based on the monitored output voltage. 
 
   
   
     2. The system of  claim 1 , wherein the controller causes the buck/boost voltage to be applied in phase with the output voltage to increase the output voltage. 
   
   
     3. The system of  claim 1 , wherein the controller causes the buck/boost voltage to be applied 180 degrees out of phase with the output voltage to decrease the output voltage. 
   
   
     4. The system of  claim 1 , including:
 switches connected to the sub-coils and controlled by the controller to allow the sub-coils to be connected in a plurality of different configurations to control the output voltage. 
 
   
   
     5. The system of  claim 1 , wherein the sub-coils within each of the stator coils include a number of turns, each sub-coil within one of the stator coils having a different number of turns. 
   
   
     6. The system of  claim 1 , wherein the buck/boost voltage source generates the buck/boost voltage at a frequency equal to a frequency of the output voltage. 
   
   
     7. A permanent magnet generator system, the system comprising:
 a permanent magnet generator that includes a number of stator coils divided into sub-coils, wherein selected sub-coils are connected to generate an output voltage; and 
 a controller connected to monitor the output voltage generated by the PMG and to apply a buck/boost voltage to sub-coils that are not connected to generate the output voltage to either increase or decrease the output voltage based on the monitored output voltage. 
 
   
   
     8. The system of  claim 7 , wherein the controller applies a buck/boost voltage in phase with the monitored output voltage if the monitored output voltage is below a desired level. 
   
   
     9. The system of  claim 7 , wherein the controller applies a buck/boost voltage 180 degrees out of phase with the monitored output voltage if the monitored output voltage is above a desired level. 
   
   
     10. The system of  claim 7 , further including:
 a plurality of switches within a switch array that are controlled by the controller to selectively connect the sub-coils together in one of a plurality of configurations based on the monitored output voltage. 
 
   
   
     11. The system of  claim 10 , wherein the controller controls the plurality of switches to connect selected sub-coils in series with the sub-coils connected to generate the output voltage. 
   
   
     12. The system of  claim 10 , wherein the controller applies a buck/boost voltage, to selected sub-coils that are not connected to generate the output voltage within a particular configuration to either increase or decrease the output voltage.